feat(editor): indentation (#2174)

* switch to default codeblock tab handling

* feat(editor): indentation

apps/client/src/features/editor/extensions/extensions.ts

@@ -10,7 +10,9 @@ import { Typography } from "@tiptap/extension-typography";
 import { TextStyle } from "@tiptap/extension-text-style";
 import { Color } from "@tiptap/extension-color";
 import { Youtube } from "@tiptap/extension-youtube";
-import SlashCommand, { SlashCommandExtension as Command } from "@/features/editor/extensions/slash-command";
+import SlashCommand, {
+  SlashCommandExtension as Command,
+} from "@/features/editor/extensions/slash-command";
 import renderItems from "@/features/editor/components/slash-menu/render-items";
 import getSuggestionItems from "@/features/editor/components/slash-menu/menu-items";
 import { Collaboration, isChangeOrigin } from "@tiptap/extension-collaboration";
@@ -46,6 +48,7 @@ import {
   Subpages,
   Heading,
   Highlight,
+  Indent,
   UniqueID,
   SharedStorage,
   Columns,
@@ -201,6 +204,7 @@ export const mainExtensions = [
     showOnlyWhenEditable: true,
   }),
   TextAlign.configure({ types: ["heading", "paragraph"] }),
+  Indent,
   TaskList,
   TaskItem.configure({
     nested: true,
@@ -311,6 +315,8 @@ export const mainExtensions = [
     view: CodeBlockView,
     //@ts-ignore
     lowlight,
+    enableTabIndentation: true,
+    tabSize: 2,
     HTMLAttributes: {
       spellcheck: false,
     },
@@ -405,7 +411,10 @@ const TEMPLATE_EXCLUDED_SLASH_ITEMS = new Set([
 const TemplateSlashCommand = Command.configure({
   suggestion: {
     items: ({ query }: { query: string }) =>
-      getSuggestionItems({ query, excludeItems: TEMPLATE_EXCLUDED_SLASH_ITEMS }),
+      getSuggestionItems({
+        query,
+        excludeItems: TEMPLATE_EXCLUDED_SLASH_ITEMS,
+      }),
     render: renderItems,
   },
 });

apps/client/src/features/editor/styles/indent.css

@@ -0,0 +1,14 @@
+.ProseMirror {
+  --indent-step: 2rem;
+}
+
+.ProseMirror [data-indent="1"] { padding-inline-start: calc(var(--indent-step) * 1); }
+.ProseMirror [data-indent="2"] { padding-inline-start: calc(var(--indent-step) * 2); }
+.ProseMirror [data-indent="3"] { padding-inline-start: calc(var(--indent-step) * 3); }
+.ProseMirror [data-indent="4"] { padding-inline-start: calc(var(--indent-step) * 4); }
+.ProseMirror [data-indent="5"] { padding-inline-start: calc(var(--indent-step) * 5); }
+.ProseMirror [data-indent="6"] { padding-inline-start: calc(var(--indent-step) * 6); }
+.ProseMirror [data-indent="7"] { padding-inline-start: calc(var(--indent-step) * 7); }
+.ProseMirror [data-indent="8"] { padding-inline-start: calc(var(--indent-step) * 8); }
+.ProseMirror [data-indent="9"] { padding-inline-start: calc(var(--indent-step) * 9); }
+.ProseMirror [data-indent="10"] { padding-inline-start: calc(var(--indent-step) * 10); }

apps/client/src/features/editor/styles/index.css

@@ -13,5 +13,6 @@
 @import "./mention.css";
 @import "./ordered-list.css";
 @import "./highlight.css";
+@import "./indent.css";
 @import "./columns.css";
 @import "./status.css";

apps/server/package.json

@@ -163,10 +163,11 @@
     "rootDir": "src",
     "testRegex": ".*\\.spec\\.ts$",
     "transform": {
+      "happy-dom.+\\.js$": ["babel-jest", { "presets": [["@babel/preset-env", { "targets": { "node": "current" } }]] }],
       "^.+\\.(t|j)s$": "ts-jest"
     },
     "transformIgnorePatterns": [
-      "/node_modules/(?!(\\.pnpm/)?(nanoid|uuid|image-dimensions|marked)(@|/))"
+      "/node_modules/(?!(\\.pnpm/)?(nanoid|uuid|image-dimensions|marked|happy-dom)(@|/))"
     ],
     "collectCoverageFrom": [
       "**/*.(t|j)s"

apps/server/src/collaboration/collaboration.util.ts

@@ -34,6 +34,7 @@ import {
   Mention,
   Subpages,
   Highlight,
+  Indent,
   UniqueID,
   Columns,
   Column,
@@ -62,10 +63,11 @@ export const tiptapExtensions = [
   }),
   Heading,
   UniqueID.configure({
-    types: ['heading', 'paragraph'],
+    types: ['heading', 'paragraph', 'transclusionSource'],
   }),
   Comment,
   TextAlign.configure({ types: ['heading', 'paragraph'] }),
+  Indent,
   TaskList,
   TaskItem.configure({
     nested: true,

apps/server/src/common/helpers/prosemirror/indent-schema.spec.ts

@@ -0,0 +1,63 @@
+import { htmlToJson, jsonToHtml } from '../../../collaboration/collaboration.util';
+
+const findFirstChild = (
+  json: any,
+  type: string,
+): any | undefined => {
+  if (!json || typeof json !== 'object') return undefined;
+  if (json.type === type) return json;
+  if (Array.isArray(json.content)) {
+    for (const child of json.content) {
+      const found = findFirstChild(child, type);
+      if (found) return found;
+    }
+  }
+  return undefined;
+};
+
+describe('indent attribute round-trip', () => {
+  it('parses data-indent on a paragraph into the indent attribute', () => {
+    const html = '<p data-indent="3">Hello</p>';
+    const json = htmlToJson(html);
+    const paragraph = findFirstChild(json, 'paragraph');
+    expect(paragraph).toBeDefined();
+    expect(paragraph.attrs.indent).toBe(3);
+  });
+
+  it('parses data-indent on a heading into the indent attribute', () => {
+    const html = '<h2 data-indent="2">Heading</h2>';
+    const json = htmlToJson(html);
+    const heading = findFirstChild(json, 'heading');
+    expect(heading).toBeDefined();
+    expect(heading.attrs.indent).toBe(2);
+    expect(heading.attrs.level).toBe(2);
+  });
+
+  it('clamps out-of-range data-indent values', () => {
+    const html = '<p data-indent="42">Too deep</p>';
+    const json = htmlToJson(html);
+    const paragraph = findFirstChild(json, 'paragraph');
+    expect(paragraph.attrs.indent).toBe(8);
+  });
+
+  it('renders nonzero indent back to data-indent on HTML serialization', () => {
+    const html = '<p data-indent="4">Round-trip</p>';
+    const json = htmlToJson(html);
+    const out = jsonToHtml(json);
+    expect(out).toContain('data-indent="4"');
+  });
+
+  it('omits data-indent for indent zero', () => {
+    const html = '<p>No indent</p>';
+    const json = htmlToJson(html);
+    const out = jsonToHtml(json);
+    expect(out).not.toContain('data-indent');
+  });
+
+  it('preserves indent through HTML → JSON → HTML', () => {
+    const original = '<p data-indent="5">Five deep</p>';
+    const json = htmlToJson(original);
+    const final = jsonToHtml(json);
+    expect(final).toContain('data-indent="5"');
+  });
+});

packages/editor-ext/src/index.ts

@@ -23,6 +23,7 @@ export * from "./lib/embed-provider";
 export * from "./lib/subpages";
 export * from "./lib/transclusion";
 export * from "./lib/highlight";
+export * from "./lib/indent";
 export * from "./lib/heading/heading";
 export * from "./lib/unique-id";
 export * from "./lib/shared-storage";

packages/editor-ext/src/lib/custom-code-block/custom-code-block.ts

@@ -1,8 +1,8 @@
-import type { CodeBlockOptions } from "@tiptap/extension-code-block";
-import CodeBlock from "@tiptap/extension-code-block";
+import type { CodeBlockOptions } from '@tiptap/extension-code-block';
+import CodeBlock from '@tiptap/extension-code-block';
 
-import { LowlightPlugin } from "./lowlight-plugin.js";
-import { ReactNodeViewRenderer } from "@tiptap/react";
+import { LowlightPlugin } from './lowlight-plugin.js';
+import { ReactNodeViewRenderer } from '@tiptap/react';
 
 export interface CodeBlockLowlightOptions extends CodeBlockOptions {
   /**
@@ -12,7 +12,7 @@ export interface CodeBlockLowlightOptions extends CodeBlockOptions {
   view: any;
 }
 
-const TAB_CHAR = "\u00A0\u00A0";
+const TAB_CHAR = '\u00A0\u00A0';
 
 /**
  * This extension allows you to highlight code blocks with lowlight.
@@ -25,7 +25,7 @@ export const CustomCodeBlock = CodeBlock.extend<CodeBlockLowlightOptions>({
     return {
       ...this.parent?.(),
       lowlight: {},
-      languageClassPrefix: "language-",
+      languageClassPrefix: 'language-',
       exitOnTripleEnter: true,
       exitOnArrowDown: true,
       defaultLanguage: null,
@@ -37,20 +37,8 @@ export const CustomCodeBlock = CodeBlock.extend<CodeBlockLowlightOptions>({
   addKeyboardShortcuts() {
     return {
       ...this.parent?.(),
-      Tab: () => {
-        if (this.editor.isActive("codeBlock")) {
-          this.editor
-            .chain()
-            .command(({ tr }) => {
-              tr.insertText(TAB_CHAR);
-              return true;
-            })
-            .run();
-          return true;
-        }
-      },
-      "Mod-a": () => {
-        if (this.editor.isActive("codeBlock")) {
+      'Mod-a': () => {
+        if (this.editor.isActive('codeBlock')) {
           const { state } = this.editor;
           const { $from } = state.selection;
 
@@ -60,7 +48,7 @@ export const CustomCodeBlock = CodeBlock.extend<CodeBlockLowlightOptions>({
 
           for (depth = $from.depth; depth > 0; depth--) {
             const node = $from.node(depth);
-            if (node.type.name === "codeBlock") {
+            if (node.type.name === 'codeBlock') {
               codeBlockNode = node;
               codeBlockPos = $from.start(depth) - 1;
               break;

packages/editor-ext/src/lib/indent.ts

@@ -0,0 +1,223 @@
+import { Extension } from '@tiptap/core';
+import {
+  Plugin,
+  PluginKey,
+  type EditorState,
+  type Transaction,
+} from '@tiptap/pm/state';
+
+export type IndentOptions = {
+  types: string[];
+  min: number;
+  max: number;
+};
+
+declare module '@tiptap/core' {
+  interface Commands<ReturnType> {
+    indent: {
+      indent: () => ReturnType;
+      outdent: () => ReturnType;
+    };
+  }
+}
+
+// Containers whose descendants must never carry an `indent` attribute. These
+// nodes own their own Tab semantics (list nesting, cell navigation, literal
+// tab) and visually conflict with our indent padding, so paragraphs and
+// headings inside them stay flat
+const NON_INDENTABLE_ANCESTORS = new Set([
+  'listItem',
+  'taskItem',
+  'tableCell',
+  'tableHeader',
+  'codeBlock',
+]);
+
+const clampIndent = (value: number, min: number, max: number): number => {
+  if (!Number.isFinite(value)) return min;
+  return Math.max(min, Math.min(max, Math.trunc(value)));
+};
+
+const hasNonIndentableAncestor = (
+  doc: EditorState['doc'],
+  pos: number,
+): boolean => {
+  const $pos = doc.resolve(pos);
+  for (let depth = $pos.depth; depth >= 0; depth--) {
+    if (NON_INDENTABLE_ANCESTORS.has($pos.node(depth).type.name)) {
+      return true;
+    }
+  }
+  return false;
+};
+
+export const Indent = Extension.create<IndentOptions>({
+  name: 'indent',
+
+  priority: 1000,
+
+  addOptions() {
+    return {
+      types: ['paragraph', 'heading'],
+      min: 0,
+      max: 8,
+    };
+  },
+
+  addGlobalAttributes() {
+    return [
+      {
+        types: this.options.types,
+        attributes: {
+          indent: {
+            default: this.options.min,
+            keepOnSplit: true,
+            parseHTML: (element) => {
+              const raw = element.getAttribute('data-indent');
+              if (raw === null) return this.options.min;
+              return clampIndent(
+                parseInt(raw, 10),
+                this.options.min,
+                this.options.max,
+              );
+            },
+            renderHTML: (attributes) => {
+              const value = attributes.indent;
+              if (value <= this.options.min) return {};
+              return { 'data-indent': String(value) };
+            },
+          },
+        },
+      },
+    ];
+  },
+
+  addCommands() {
+    return {
+      indent:
+        () =>
+        ({ state, tr, dispatch }) => {
+          return updateIndent(state, tr, dispatch, this.options, +1);
+        },
+      outdent:
+        () =>
+        ({ state, tr, dispatch }) => {
+          return updateIndent(state, tr, dispatch, this.options, -1);
+        },
+    };
+  },
+
+  addKeyboardShortcuts() {
+    const isInIndentableBlock = (): boolean => {
+      const { $from } = this.editor.state.selection;
+      if (!this.options.types.includes($from.parent.type.name)) return false;
+      for (let depth = $from.depth - 1; depth >= 0; depth--) {
+        if (NON_INDENTABLE_ANCESTORS.has($from.node(depth).type.name)) {
+          return false;
+        }
+      }
+      return true;
+    };
+
+    return {
+      Tab: () => {
+        if (!isInIndentableBlock()) return false;
+        this.editor.commands.indent();
+        return true;
+      },
+      'Shift-Tab': () => {
+        if (!isInIndentableBlock()) return false;
+        this.editor.commands.outdent();
+        return true;
+      },
+      Backspace: () => {
+        const { $from, empty } = this.editor.state.selection;
+        if (!empty) return false;
+        if ($from.parentOffset !== 0) return false;
+        if (!isInIndentableBlock()) return false;
+        if ($from.parent.attrs.indent <= this.options.min) return false;
+        this.editor.commands.outdent();
+        return true;
+      },
+    };
+  },
+
+  addProseMirrorPlugins() {
+    const types = new Set(this.options.types);
+    const min = this.options.min;
+
+    return [
+      new Plugin({
+        key: new PluginKey('indentNormalizer'),
+        appendTransaction: (transactions, _oldState, newState) => {
+          if (!transactions.some((tr) => tr.docChanged)) return null;
+
+          const tr = newState.tr;
+          let modified = false;
+
+          newState.doc.descendants((node, pos) => {
+            // Containers: descend so we can find paragraph/heading children.
+            if (!types.has(node.type.name)) return true;
+
+            if (node.attrs.indent <= min) return false;
+
+            if (hasNonIndentableAncestor(newState.doc, pos)) {
+              tr.setNodeMarkup(
+                pos,
+                undefined,
+                { ...node.attrs, indent: min },
+                node.marks,
+              );
+              modified = true;
+            }
+
+            // paragraph/heading don't contain other paragraphs/headings —
+            // never descend into their inline content.
+            return false;
+          });
+
+          if (!modified) return null;
+          // Normalisation must not show up as a separate undo step;
+          // otherwise undo would re-introduce the illegal indent.
+          return tr.setMeta('addToHistory', false);
+        },
+      }),
+    ];
+  },
+});
+
+function updateIndent(
+  state: EditorState,
+  tr: Transaction,
+  dispatch: ((tr: Transaction) => void) | undefined,
+  options: IndentOptions,
+  delta: number,
+): boolean {
+  const { selection } = state;
+  const { from, to } = selection;
+  const types = new Set(options.types);
+  let updated = false;
+
+  state.doc.nodesBetween(from, to, (node, pos) => {
+    // Skip non-block nodes (text, inline atoms) up front.
+    if (!node.type.isBlock) return false;
+
+    // Don't descend into containers whose children must stay flat — handles
+    // multi-block selections that span across e.g. a list-item or table-cell.
+    if (NON_INDENTABLE_ANCESTORS.has(node.type.name)) return false;
+
+    if (!types.has(node.type.name)) return true;
+
+    const current = node.attrs.indent as number;
+    const next = clampIndent(current + delta, options.min, options.max);
+    if (next === current) return false;
+
+    tr.setNodeMarkup(pos, undefined, { ...node.attrs, indent: next });
+    updated = true;
+    return false;
+  });
+
+  if (!updated) return false;
+  if (dispatch) dispatch(tr);
+  return true;
+}